Mary is based on the character of the same name from the parallel novel Mary Reilly.
Mary is the daughter of Dr. Lydgate and lives with him in Victorian England. She is also a close friend of Dr. Henry Jekyll, who has unreciprocated feelings for her. One day, she helps him calm down as her father comes to visit him in his laboratory to hear about his new invention -- a serum that can give a man power over his darkness. Jekyll hopes that Dr. Lydgate will give him entry into the academy to finish his serum, however, once Lydgate figures out that this is Jekyll's intention, he tells Jekyll that his work is too dangerous. Lydgate calls Mary to come with him as he leaves, though Mary pauses to comfort Jekyll. ("Strange Case")
At a party, Mary and her father are approached by Mr. Hyde, who introduces himself as a friend of Dr. Jekyll's. She is immediately intrigued by him and allows him to kiss her hand, but a suspicious Lydgate sends Mary away to get them drinks. This diversion allows the two men to talk, although their conversation is interrupted when Mary returns. Later on the streets, Mary is walking by and hears Hyde calling her. This time, he has come to talk to her about Jekyll's feelings for her, but Mary responds that she could never love him. However, she acknowledges that the traits Jekyll lacks are apparent in Hyde, and they kiss and later sleep together. However, when Mary awakens she finds Jekyll by her side, she becomes concerned that he may have done something to Hyde, only to discover that Hyde is the resulting split personality from Jekyll taking his own serum. Jekyll, angry and heartbroken at Hyde and Mary's betrayal, accidentally pushes Mary out the window to her death. In shock of what he's done, Jekyll ingests the serum directly after to make Hyde manifest, in order to pin him as the murderer. ("Strange Case")
|Once Upon a Time: Season Six|
|"The Savior":||"A Bitter Draught":||"The Other Shoe":||"Strange Case":||"Street Rats":||"Dark Waters":||"Heartless":||"I'll Be Your Mirror":||"Changelings":||"Wish You Were Here":||"Tougher Than the Rest":|
|"Murder Most Foul":||"Ill-Boding Patterns":||"Page 23":||"A Wondrous Place":||"Mother's Little Helper":||"Awake":||"Where Bluebirds Fly":||"The Black Fairy":||"The Song in Your Heart":||"The Final Battle Part 1":||"The Final Battle Part 2":|